A known boom support is presented in German publication nr 2 311 697. That support can be moved in the vertical direction and turned on a pillar which has a round cross-section. This boom support is locked on the pillar by tightening a brake wedge against the surface of the pillar. The wedge stands out from a sleeve-like gliding part. The holder or support consists of an extension, on which the boom is situated.
The above-mentioned boom holder has various shortcomings. For example, it is impossible to get the same pressing or locking force repeatedly after one or several openings. Also, it is desired for a boom support to give in during training or use when pressed down with a certain force. With the mentioned boom holder, there is no control for the locking force of the tightening apparatus, and it is also impossible to tighten the holder over and over again with the same locking force. In addition, the gliding part of the holder is so wide on the pillar that it can turn crosswise a little when the holder is locked on the pillar. This causes the locking forces to vary uncontrollably because the gliding part or the pressing wedge can press even depressions in the pillar surface with their sharp edges.
With the cupholder according to the present invention, these shortcomings are avoided.